POJ 1517

题意

求e

思路

注意前三个输出就ok了

#include <iostream>
#include <cmath>
#include <algorithm>

using namespace std;

int main(){
    double sum = 2.5;
    cout<<"n e"<<endl;
    cout<<"- -----------"<<endl;
    for(int i = 0;i<=9;i++){
        if(i==0) cout<<"0 1"<<endl;
        else if(i==1) cout<<"1 2"<<endl;
        else if(i==2) cout<<"2 2.5"<<endl;
        else{   
            double temp=1;
            for(int j=1;j<=i;j++){
                temp*=j;
            }
            sum  =  sum + 1/temp;
            cout<<i<<" "<<fixed<<sum<<endl;
        }
    }
    return 0;
}